Apparatus for profiling operations



' Nov. 7, 195% 111A. KESTELL APPARATUS FOR PROFILING OPERATIONS 14 Sheets-Sheet 1 Filed Aug. 21, 1945 IIIIIIIIIIIIIIII T. A. KESTELL APPARATUS FOR PROFILING OPERATIONS Nov. 7, 1950 14 Sheets-Sheet 2 Filed Aug. 21, 1945 Nov. 7, 1950 T. A. KESTELL APPARATUS FOR PROFILING OPERATIONS 14 Sheets-Sheet 3 Filed Aug. 21. 1945 T. A. KESTELL APPARATUS FOR PROFILING OPERATIONS Nov. 7, 1950 14 Sheets-Sheet 4 Filed Aug. 21, 1945 Nov. 7, 1950 T. A. KESTELL APPARATUS FOR PROFILING OPERATIONS Filed Aug. 21, 1945 14 Sheets-Sheet 5 l l l T. A. KESTELL APPARATUS FOR PROFILING OPERATIONS Nov. 7, 1950 Filed Aug. 21, 1945 14 Sheets-Sheet 6 Nov. 7, 1950 'r. A. KESTELL APPARATUS FOR PROFILING OPERATIONS 14 Sheets-Sheet 7 Filed Aug. 21, 1945 Nov. 7, 1950 T. A. KESTELL 2,529,026

APPARATUS FOR PROFILING OPERATIONS 14 Sheets-Sheet 8 Filed Aug. 21, 1945 Nov. 7, 1950 'r. KESTELL 2,529,026

' APPARATUS FOR PROFILING OPERATIONS Filed Au 21, 1945 14 Sheets-Sheet 9 imam v 714w! w 7% SW Nov. 7, 1950 'r. A. KESTELL APPARATUS FOR PROFILING opmnons l4 Sheets-Sheet 10 Filed Aug. 21, 1945 Nov." 7, 1950 T. A. KESTELL 2,529,026

- APPARATUS FOR PROFILING OPERATIONS Filed Aug. 21. 1945 14 Sheets-Sheet 11 Nov. 7, 1950 "r. A. KESTELL APPARATUS FOR PRGFILING OPERATIONS 14 Sheets-Sheet 13 Filed Aug. 21, 1945 Nov. 7, 1950 1'. A. KESTELL APPARATUS FOR PROFILING OPERATIONS 14 Sheets-Sheet 14 Filed Aug. 21, 1945 Patented Nov. 7, 1950 APPARATUS FOR PROFILING OPERATIONS Thomas Aubrey Kestell, Thurmaston, England,

assignor to Power Jets (Research & Development) Limited, London, England Application August 21, 1945, Serial No. 611,853 In Great Britain January 27, 1944 9 Claims.

The present invention consists in a method of and apparatus for performing turning, milling, grinding and like shaping or working operations to produce articles of irregular contour or profile, and is of particular application, for example, in the profiling of turbine blades.

The invention has been evolved primarily to provide a method of and apparatus for quantity production of a particular form of turbine blade the surface of which, whilst roughly approximating to segments of cylindrical surfaces, are in fact of profile which .varies continuously in all three dimensions. The blade design calls for exceptional accuracy both dimensionally and in regard to surface finish, as well as consistency in profile, dimensions and quality of finish as between individual blades of similar "design produced on the mach ne.

It is also advantageous for the apparatus to be in the form of 'a self-contained compact unit which may be installed on any existing lathe or the like, and it is also necessary to obtain a substantial'degree of rigidity to ensure accuracy and consistency in the profile to be formed.

With these and other objects in view, the invention provides a method of and apparatus for profiling according to which the work is, rotatably mounted about a work axis, and reciprocatory relative motion is effected between the work axis and the tool, involving rocking about a further axis, the extent of said rocking being varied in accordance with a traversing movement of the work relative to the tool, which movement is either along, or has a component along, either or both of said axes.

According to one form of embodiment, the apparatus according to the invention comprises work-mounting means embodying a primary drive and a secondary drive, of which the primary drive'is operable to rotate the Workabout an axis which is itself rocked arcuately under the influence of the secondary drive. The primary drive and the secondary drive may be positively geared with a common drive input to the workmounting means. Preferably, the secondary drive operates through a barrel-like profile cam engaged ,by a follower rigidly coupled to the mounting for the primary drive. In such an embodiment, the work-mounting means can be adapted as a unit for installation on an, existing grinding or like machine.

The machine according to the invention is intended to be capable of dealing with the operations'of profile turning, milling and grinding the convex and concave faces of the" blades, but in preferred production methods the blades are produced from forgings, castings or other preformed shapes, leaving the final profiling finish tobe applied by turning, illing and/or grinding the concave and convex faces. In any event, although each machine, in the preferred form, is

. adapted for all the various operations, production methods will preferably utilise a machine for each operation of the required series.

Preferably a machine according to the invention incorporates a base casting providing sliding surfaces and the usual guides for the tool and work-mounting, the tool being typically a grinding head or any other suitable form of cutting tool, whereas the work-mounting is in fact a profiling head embodying the essential features of the present invention.

According to a further feature of the invention, means are provided for applying a predetermined cut to the work at the end of each traversing -movement, such out being applied The above mentioned and further features of the invention will appear from the description hereinunder which is given by way of example in respect of three forms of embodiment of the inventionand illustrated in the accompanying drawings in which:

Fig. 1 is a diagrammatic perspective view of a first form of embodiment;

Fig. 2 is a part elevation of said emb in section on the lineCD of Fig. 3; I

Fig. 3 is an end section on the line AB of Fig. 2; Fig. 4 is a section on'the line EF of Fig. 3;

Fig. 5 is a right hand end section on line P6} of Fig. 6;

Fig. 6 is a section on the line GH of Fig. 5; Fig. 7 is a detail view in'the directionof the arrow X in Fig. 5; I

Fig. 8 is a detailview; 1 Fig. 9 is a partial view in. sectional Fig. 10 is a partly-diagrammatic section on JK' of Fig. 9 with the work turned through odiment 3 Fig. 11 is a continuation of Fig. Fig. 12 is a plan view; Fig. 13 is a front elevation in section of a second form of embodiment;

Fig. 14 is an .enlarged detail of Fig. 13 in plan 5 view;

Fig. 15 is an end view in part section of Fig. 18 turned through 90;

Fig. 16 is apart end view; Fig. 17 is a detail view;

1 Fig. 18 is a plan view in section of a third form of embodiment;

Fig. 19 is a detail of said embodiment;

Figs. 20 and 21 are detail views relating to turning operations;

15 Fig. 22 is a general plan view of a machine assembly for internal grinding;

Fig. 23 is a general front view of a machine assembly for external grinding.

In Figs. 1-12 which represent one form of embodiment for use when, for example turbine blades are required to be ground on their external convex faces, one, two or more blades 6 (Figs. 9 and 12) are engaged upon a mandrel l,

the whole assembly presenting some rough ap- 25 proximation to cylindrical form.

The means for holding and accurately positioning said blades 6 on the mandrel I are described in detail in Patent No. 2,475,900.

The mandrel I with the blades 6 accurately so positioned on it is mounted co-axially on a work bears on a barrel-like cam I4. The said cam I4 4 may be designated the profiling cam and is driven for rotation about a cam shaft II, the effect of said rotation being to impart a rocking movement to the sleeve I0 and consequently to the shaft 9.

Drive is imparted to the work shaft 9 through a spur gear wheel 4 mounted on the cam shaft I1 and engaging teeth I2 provided externally on an annulus 25 journalled on the exterior surface of the eccentric sleeve I0. The annulus 25 is also provided with internal teeth I3, which engage a 5 pinion I8 mounted on shaft 9. Cam shaft I1 is driven through pulley 2 from a main drive comprising an electric motor 244, cone V pulley 245,

countershaft 246 and belting 241 (Fig. 23).

Irregularities of profile of the blades 6 are resolved as departures from cylindrical form of the profile presented by the blades 6 to the grinding wheel I and thus depend upon the rocking or eccentric movement of the sleeve III which is accurately determined by the cam surface I4 and the driving speed relationship between the blades 6 and the cam I4. The form of cam I4 and the gear ratio used between said cam and the blades are necessarily, therefore, worked out with an exceptionally high degree of accuracy to produce the requisite and predetermined departure from cylindrical form about the axis of shaft 9.

In order to traverse the blades 6 across the this purpose the apparatus comprises a lever 26 (Fig. 2) journalled at its lower end to the main casting 3 of the profiling head and carrying at its upper end a cam roll 21 which projects sideways into a slot 28 in the eccentric sleeve III. The lever 26 is adapted to rock about a transverse axis 29, its rocking movement being controlled by a second cam roll 80 carried on the lever 26 and projecting into a track 9| in the face of a cam 92 0 directly coupled to a worm wheel 93 (Fig. 3)

driven by worm shaft 242 from the main drive input. The track 9i in the face of the cam 92 is of approximately heart-shape or other suitable formation so as to ensure that one rotation of the cam 92 traverses the eccentric sleeve I0 completely in and out within the limits of its movement relative to the profile head 3 and of the movement of the blades 6 relative to the grinding wheel I. Any usual means may be provided to ensure variation of the speed of traverse, such variation being achieved either under direct control of the operator or on setting up the machine.

At the end of each traverse movement of the blades 6 it is necessary to apply additional cut, i. e. to advance the blades in a radial direction towards the grinding wheel 1. According to the invention this is performed automatically by means of the following arrangement.

An operating handle 94 (Figs.' 5 and 7) is mounted on lever 95 fixed to spindle 96 and can be moved radially round the spindle centre between two extremes or intermediately by means of stops 230 (Fig. 7) consisting of removable pins.

Movement of handle 94 moves an eccentric 91 5 mounted on spindle 96 and forming a stop for lever 98 (Fig. 6) thus limiting the movement of roller I01 carried on lever 98 into the recess in cam I02, the said roller I01 being urged into recess wheel I06 being dragged back with the pawls I03,

I04, a plunger I05 in recess 232 in the profile head 3 is held engaged with ratchet wheel I06 by spring 0 233. The end of plunger I05 has two half pitched teeth 34 (Fig. 8) which engage the teeth of ratchet wheel I06 in the full or half pitched position. Upon ejection of roller, I0'I from recess 35 of cam I02 the pawls I03, I04, move wheel I06 by an amount substantially equal to the movement of the said pawls, thus rotating shaft I08 in a fixed internally threaded bush I09 engaging with external threads on shaft I08. Consequently said shaft I08 together with bracket III) and profile head 3 is advanced towards the grinding wheel I. The ratchet wheel I06 (Fig. 5) is journalled on shaft I08 to which disc II I is taper pinned by pin 36 and interposed between said wheel I06 and disc I II is a friction washer I I 2. The members I06, III, II2 are held in engagement with one another by means of spring II3 abutting at one end against a collar H4 and at its other end against the boss of ratchet wheel I06 through a.

grinding wheel -'I and at the same time to control spacing washer H5. The collar H4 is retained the profile of said blades by means of cam I4 it by locking nuts H6, III, which are in threaded is necessary to impart a traverse movement to sleeve I0 whereby the cam roll I9 is traversed along the surface of cam I4 so that the irregularity of profile required is achieved automatically ,engagement with shaft I08.

It is necessary to provide some indication to the operator when suflieient total out has been applied and it is advantageous for the apparatus to in the course of this traverse movement. For prevent automatically the application of additional cut after the application of the final finishing cut.

For this purpose the apparatus according to the invention comprises a stop II8 (Fig. 5) in the form of a hollow plunger adapted to be moved under the influence of aspring I28 and mounted in the profile head slide casting II8 so that it canbe clamped by an eccentric I28 mounted on spindle 235 which can be rotated to clamp or unclamp plunger II8 by a wedging action to retain a predetermined longitudinal position. The stop H8 is engaged by a screw I2I carried in bracket H8 and locked thereto by lock nut I22.

011 release of plunger II8, spring I23 forces plunger H8 in contact with stop screw l2| to record the inward limiting position of profile head 8. It is then only necessary to reclamp the stop a to the profile head slide us.

cation of out. When stop screw I2I contacts stop I I8 further movement of profile head 3 is prevented, and therefore rotation of ratchet wheel I88 is unable to rotate shaft I88, and consequently slip will take place between ratchet wheel I88 and disc III. (A small departpre from this setting if required can be obtained by adjusting the setting of stop screw I2I.)

If required the automatic feed mechanism may berendered inoperative and" the feed cut applied by hand, or both automatic and manual cut may be applied. I

For manual cut, a ball handle 234 is provided rigid with threaded shaft I88 and micrometer dial 238. Cut may be applied by setting the ball handle graduations on the dial 288 against a' fixed datum line on the bracket II8 rigid with profile head 3.

The grinding wheel 1 may be mounted on a slide 252 (Fig. 23) which can be moved at rightangles to the directionof movement of the saddle 253 so that the wheel 1 can be moved forward to engage a diamond dresser 248, so that after dressing, the working face of said wheel 1 occupies a constant position relative to the fixed stop II8 on the profile head slide I I8.

The apparatus also comprises a dust cover 231.

According to a further feature in the invention, the apparatus comprises means for providing an adjustable gear ratio between the profile cam I4 and the workshaft 8. For this purpose, as shown in Figs. 1-4, the cam I4 is mounted on a sleeve I82 which is journalled on the cam shaft I1 and in the end cover I88.

The cam sleeve I82 has gear teeth 81 which mesh with a pinion I84 mounted on a stud I85 on the profile head 3.. Rigid with pinion I84 is a second pinion I88, which in turn meshes with a third pinion I81 rigid with cam shaft I1.

As drawn, the profile cam I4 together with its sleeve I82 will have a gear ratio relative to the cam shaft I1 such that its rotational speed is twice that of the shaft I1. This will enable the profile cam I4 to make a complete revolution while the workshaft 8 turns through 180, and thus if two blades 8 are mounted on a mandrel I carried by the workshaft 8 the whole periphcry of the profile cam I4 can be used to control the profile of one blade, and on its second revolution will control the profile of the other blade.

The profile cam I4 together with its sleeve I82 can be directly attached to the cam shaft I1 and thus have a 1 to 1 ratio with the work shaft 8, or by changing two or more of'the gears recan be driven at three or four times the speed of the cam shaft I1 and workshaft 8.

The workshaft 8 is located by means of the following arrangement. At its front end the shaft 8 is journalled in a double conical bearing bush I24. At the rear end, the pinion I8 is secured to shaft 8 through a sleeve I25 and washer I28 by means of nut 88. The sleeve I25 is journalled in a bush 41 (Fig. 2) carried in an extension I28 of the eccentric sleeve I8. A thrust washer I21 is held in contact with the end face of bush 41 by spring I28 which consequently holds the work shaft 8 back into its double conical bearing bush I24.

The above described arrangement for shaft location is used in the case of grinding operations only. In the case of turning operations (which will be described hereinunder) a similar arrangement is used except that the spring I29 is replaced by lock nuts I88 (Fig. 13).

According to a further feature of the invention means are provided to absorb any slack in the traverse mechanism at the time of grinding the end faces of the blade.

In the case of external grinding as illustrated in Fig. 2, a spring pressed plunger I3I is carried in the profile head casing 3 and when the root shoulder ofthe blade is reached by the grinding wheel 1, plunger .I3I abuts against an abutment face I82 carried on the eccentric sleeve arm I5, thus taking up any and slack.

The apparatus according to the invention further comprises a steady device in the form of a steady bracket I38 (Figs. 9 and 12) secured to the eccentric sleeve I8 and carrying a steady bracket I 48 provided at its right hand end with a conventional form of lathe type centre I4I (as normally'mounted in a lathe tail stock) mounted on the centre line of shaft 8 and located in a conical recess I42 in mandrel I.

Rigidity of the assembly is obtained by means of a tie bar I43 secured to bracket I38 by a pin I44 and to bracket I48 by adjustable nuts 81, 88 which enable alignment to be maintained between the lathe type centre MI and shaft 8.

Bracket I48 is in the form of a trough to catch cutting lubricant which is then drained away through pipe 88.

In the case of blades which have extra length and/or a very thin trailing edge, there is a tendency for this edge to lift off the supporting mandrel due to the grinding action. For this purpose a spring loaded steady is provided.

This comprises a disc I58 (Figs.9-12) mounted adjacent to and slightly in advance of the working face of the grinding'wheel 1 (i. e. bearing on the blade 8) and nearer to the root of said blade than the grinding wheel I. The disc I58 is integral with a spindle I51 and is journalled in a bearing I52 carried at the lower end of a lever I58 fixed to a fulcrum pin I 54 which is joumalled in a bracket I55 fixed to the grinder head. A rod I58 is attached to lever I53 by a .pin I51. The rear end of rod I58 is attached head slide I 2| by spring I 88 which causes disc I58 to be yieldable away from blade 8.

This arrangement ensures that the disc I58 retains its setting relative to the blade 8 irrespective of the diameter of the grinding wheel 1.

In order to allow the root shoulder of the blade 6 to be ground it is necessary for the disc I50 to be removed and subsequently replaced on the reverse traverse of the said blade. To enable this to be done automatically a Bowden cable I66 is attached to lever I60 by means of a shackle I10 and pin "I. A casing I61 for the Bowden cable I66 is adjustably connected to cover I13 (which is bolted to the rear of grinder head H9) by means of an adjusting screw I68 and lock nut I69.

The end of Bowden cable I66 remote from grinder head I I9 is connected to lever I14 (Fig. 11) by shackle I15 and pin I16. The casing I61 is adjustably connected to the profile head by screw I11 and lock nut I18. The lever I14 is fulcrumed on a pin I19 carried in bracket I80 attached to the profile head 3 and is adapted to engage with a projection I 8I (Fig. 6) on the feed cam I02 in a timing relationship such that the projection I50 will be lifted clear of the blade 8 before its root shoulder reaches the grinding wheel 1 and will be returned to the blade 6 after the latter has travelled back an equal distance subsequent to the grinding of the said root shoulder.

The distance between the centre W of workshaft 9 (Figs. 3, 5, 16) and the centre S of eccentric sleeve I may be regarded as the eccentric throw of said sleeve. It is advantageous to be able to adjust the ratio of the distance between the said centre S and the centre of roller I9 to the said eccentric throw. For this purpose the roller I9 is mounted in a removable block I38 for which other blocks having any desired value of this ratio may be substituted.

Figs. 13-17 illustrated a second form of embodiment as applied for example to grinding the concave face of a turbine blade, i. e. internal operations.

The general arrangement and principles of operation of the apparatus of Figs. 13-17 are substantially similar to those already described in connection with Figs. 1-12 and differ only as regards the method of mounting the blades 6 on the work shaft 9, the position of the eccentric sleeve arm I and the means for taking up end slack.

For internal grinding the blades 6 are mounted in a chuck the construction of which is more fully described in Patent No. 2,475,900.

According to the desired direction of rotation of the work shaft 9 it is necessary to change the position of the roll I9 to ensure that the reaction due to driving the shaft 9 will force the roll I9 against the profile cam I4 and thus assist the spring I6 and ensure that the roll I9 will always be in contact with the cam I4.

To this end the eccentric sleeve arm I5 used for external operations (Figs. 1-12) is replaced by a substantially vertical eccentric sleeve arm I31 (Fig. 16) used for internal operations, but these condtions may be reversed.

The means for absorbing slack in the traverse mechanism when operating on the root shoulder of the blade 6 consist in this case of a roller I33 (Fig. 17) pivoted on a pin I34 in a plunger I35 carried in a sleeve I36 which is mounted on the eccentric sleeve arm I31. At the end of the traverse corresponding to a position for grinding the root shoulder of blade 6, roller I33 abuts against an abutment face (not shown) on the profile head 3, thus compressing spring 233 and holding back the eccentric sleeve I0 to the ex- 8. tent of the slack in the whole of the traverse mechanism.

Figs. 18 and 19 show a simplified third form of embodiment applicable to both internal and external operations.

The profile cam I4 is carried on a, sleeve 2I2 journalled on cam shaft I1 and is secured to said sleeve 2I2 by nut 2I3.

The eccentric sleeve is journalled at the profile cam end on bush 2 I4 and at the work end in a flanged bush 2I5 carried on a profile head extension 2I6. Ring gear 38 is journalled in the profile head at 2 I1 and in the profile head extension 2I6 at 2I8.

Cam shaft I 1 is journalled in a bush 2 I 9 carried in the profile head 3 and in a bush 220 mounted in sleeve 203 which is carried in bush 22I and bush 222 in the profile head 3.

A pinion 42 is rigid with camshaft I1 and a pinion 43 is keyed to sleeve 203 by key 204 and nut 205. The sleeve 203 is journalled on the profile cam shaft I1 and extends lengthwise towards said cam and has an end flange 206 provided with a locating aperture 201 engaging with a dowel 208 fixed to the profile cam I4.

The ring gear 38 in this embodiment corresponds to the annulus 25 in the embodiment of Figs. 1-12 and is provided in a similar manner with internal teeth 238, but in this case has two sets of external teeth 40, 4I adapted to mesh with the pinions 42, 43 respectively. The internal teeth 238 engage with the pinion 239 on the workshaft 9.

Thus sleeve 203 rotates with profile cam I 4 while cam shaft i1 rotates idly and consequently the ring gear 38 is driven by pinion 43. The profile cam shaft 51 has an annular flange 209 provided with an aperture 2l0 which can engage with dowel 2H (Fig. 19) carried on the profile cam I4 and in that case cam shaft I1 rotates with cam I4 while sleeve 203 is idle and in this case ring gear 38 is driven by pinion 42.

The ring gear 38 in this embodiment does not take part in the traversing movement which takes place between the internal teeth 238 and the workshaft pinion 239.

Consequently the profile cam I4 being designed to work with a given gear ratio, the position of the dowel 208 or 2H determines automatically the gear ratio which will be used.

For two blades on a chuck or mandrel a 2:1 gear ratio will be required (Fig. 18) and gear 38 must be driven by pinion 43. Therefore profile cam I 4 will be required to engage sleeve 203 and dowel 208 will be provided. For 3:1 ratio (Fig. 19), gear 38 must be driven by gear 42, and profile cam I4 will be given dowel 2I I so as to engage with cam shaft I1.

This arrangement is more compact, is simpler for gear-changing, and gives better control between the workshaft 9 and cam-shaft I1.

If the machine is intended to perform a cutting or other working operation, as distinct from grinding, it is merely a question of replacing the grinding wheel by a suitable tool. For example, for turning operations, as illustrated in Figs. 20 and 21, the grinding wheel is replaced by a turning tool 23I for external operations, or a boring bar 243 for inside turning.

In connection with the grinding operation, the accuracy of form of the grinding wheel is a. matter of considerable importance, and a grinding wheel dressing device 248 provided with a diamond (Figs. 22 and 23) is mounted at some appropriate position so that the movement of the grinding head 249 away from the operative position brings the diamond into its correct position for dressing the wheel I (Fig. 22) or I (Fig. 23), the nature of the dressing device 248 preferably being such that the grinding wheel is dressed on its periphery with a radius corner on the end face. The grinding spindle 240 (Figs. 14 and 22) for internal, grinding is preferably mounted so that the said spindle 240 is at a small angle (e. g. about relative to the workshaft 9 viewed in plan, and as the dresser movement when dressing the periphery of the grinding wheel is parallel to the workshaft, the grinding wheel 1, is dressed to the form of a frustum of a cone; the frustum method of dressing the grinding wheel ensures that it tends to retain its original maximum diameter, which is essential to the profile grinding if irregularities are to be avoided.

Figs. 22 and 23 show-a preferred arrangement of the various parts of the machine for internal and external grinding respectively. A base casting 256 serves as a support and the saddle 253,

can slide over the face 251. An electric motor 244 drives cam shaft l1 via countershaft 246, belting 241 and pulley 2. From said countershaft 246 belting 248 drives a pulley 254 coupled to and thence driving worm shaft 242 for effecting the traverse of the work by the tool. A handwheel 255 is provided for manual operation and acts as a flywheel.

Means are provided for moving the internal grinding wheel I forward for example in the form of a screw thread while maintaining its angle of inclination so that the working face of the wheel I will always occupy the same position after dressing.

The usual provision is made for lubrication o the mechanism and for supply of cutting lubricant to the working surface of the tool through the workshaft 9 for internal operation and externally for external operations.

If at any time the machine is intended to be adapted for normal grinding and metal-working operations as distinct from profile-grinding and working the eccentric sleeve it may be locked to the profiling head with the chuck shaft in a fixed setting, or a cylindrical cam may be used instead of the profile cam. In other words, the fact that the machine is adapted for profilegrinding operations does not prevent it from being used for normal grinding and other working operations.

I claim:

'1. In a profiling machine, a work support mounted for rotational movement eccentrically within a housing and for traversing movement together with said housing, means for rotating said work support about a work axis, a tool support, means for traversing said housing together with said work support relative to said tool support, said housing being mounted forrocking about an axis other than the work axis; and means for variably rocking said housing comprising cam means mounted for rotation about a third axis, a follower for said cam means, means for traversing said cam means relative to said follower whereby the follower is moved circumferentially and axially over the surface of said cam means, and means for transmitting the movement of said follower to said housing whereby when the cam follower is moved over the cam surface the amplitude of the rocking movement of the housing is automatically varied in accordance with variations in the profile of said cam means; and means for driving said cam means together with said work support in synchronism. 2. In a profiling machine for forming a three dimensional profile, a tool support, a workshaft home for rotation in a Journal located within and disposed eccentrically with respect to a housing which is itself mounted for rocking about an axis other than the workshaft axis, means for rocking said housing comprising a three dimensional cam mounted for rotation together with said workshaft and a cam follower mounted on said housing, and means for moving said housing lon itudinally relative to said cam and tool support hereby the cam follower is moved circumferentially and axially over the cam surface and the amplitude of the rocking movement of the housing is automatically varied in accordance with circumferential and axial variations in the profile of said surface.

3. A machine according to claim 2 comprising means for detachably securing work to said workshaft,- and means for yieldably bearing on said work and adapted to be released from said work during one traversing movement of the work and replaced during a subsequent reverse traversing movement.

4. In a profiling machine for forming a three dimensional profile, a workshaft borne for rotation in a journal located within and disposed eccentrically with respect to a housing, said housing being itself mounted in a journal within an outer casing, means for rocking said housing about said journal, the journal of said workshaft being located within the periphery of the journal of said housing, means for detachably securing the work to said workshaft, and means for yieldably bearing on said work and adapted to be released from said work during one traversing movement of the work and replaced during a subsequent reverse traversing movement, said means being adapted to occupy a constant spatial relationship with said work.

5. In a, profiling machine for forming a three dimensional profile, a workshaft borne for rotation in a journal located within and disposed eccentrically with respect to a housing, said housing being itself mounted for rocking in a journal within an outer casing, means for rocking said housing about said journal comprising a three dimensional cam having a profile corresponding to the required profile and mounted on a shaft totatable together with the workshaft, the journal of said workshaft being located within the periphery of the journal of said housing, a pinion rigidly mounted on said shaft, and an annulus journaled on said housing and provided with internal and external teeth of which the said internal teeth drivably engage with said pinion on said workshaft and the said external teeth drivably engage with another pinion rigid with the shaft on which said cam is mounted.

6. In a profiling machine for forming a threedimensional profile, a workshaft borne for rotation in a journal located within and disposed eccentrically with respect to a housing which is itself mounted in a journal within an outer casing, the journal of said workshaft being located within the periphery of the journal of said housing. and the said housing being associated with a primary drive operable to rotate said shaft and with a secondary drive operable to rock said housing through a cam cooperating with a follower associated with said housing, a pinion rigidly mounted on said shaft and an annulus journaled on said housing and provided with in ternal teeth and with two series of external teeth of which the said internal teeth drivably engage with said Pinion on said workshaft, and the two series of external teeth drivably engage as to one of said series with a pinion rigid with a driven shaft on which said camis mounted and as to the other of said series with a pinion rigid with a sleeve borne for rotation on said cam shaft, means being provided for securing the said cam selectivel either to the cam shaft or to said sleeve on said shaft.

'7. In a profiling machine for forming a threedimentional profile, a workshaft borne for rotation in a journal located within and disposed eccentrically with respect to a housing, said housing being itself mounted in a journal within an outer casing, the journal of said workshaft being located Within the periphery of the journal of said housing, and the said housing being associated with a primary drive operable to rotate said shaft and with a secondary drive operable to rock said housing through a cam cooperating with a follower associated with said housing, said housing being provided with a steady device comprising an extension of said housing carrying a semi-circular bracket which is secured to a tie bar by adjustable securing means, the other end of said tie bar being secured to said housing.

8. A profiling machine, a work support mounted for rotational movement eccentrically within a housing and for traversing movement together with said housing, means for rotating said work support about a work axis, a tool support, means for traversing said housing together with said work support relative to said tool support, said housing being mounted for rocking about an axis other than the work axis; and means for, variably rocking said housing comprising cam means mounted for rotation, a follower for said cam means, means for traversing said cam means relative to said follower whereby the follower is moved circumferentially and axially over the surface of said cam means, and means for transmitting the movement of said follower to said housing whereby when the cam follower is moved over the cam surface the amplitude of the rocking movement of the housing is automatically varied in accordance with variations in the profile of said cam means; means for driving said cam means together with said work supportfand gearing between the work support and the cam means for providing a predetermined speed ratio between the work support and the cam means.

9. In a profiling machine for forming a. three dimensional profile, a work support mounted for traversing movement and for rotational movement about a work axis, means for rotating said work support, a tool support, a housing within which said work support is eccentricall mounted and itself mounted for traversing movement together with said work support and for rocking movement about an axis other than the work axis, means for traversing said housing together with said work support, means for mounting for rotational movement a cam of approximately cylindrical form having a profile corresponding to the required profile and varying circumferentially and axially over the cam surface, means to rotate said cam mounting, a follower for said cam supported on a mounting, means for transmitting the movement of said mounting to said housing whereby upon traversing movement of the work support and housing relative to the tool support and cam mounting, the cam follower is moved circumferentially and axially relative to and over the profiled surface of the cam and the housing is thereby rocked to an extent which varies automatically in accordance with variations in the profile of said cam surface; and gearing between the work support and the cam mounting for providing a predetermined speed ratio between said support and said mounting.

THOMAS AUBREY KESTELL.

REFERENCES CITED The following references are of record in the file of this patent:

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